Ultra wideband-type technology is distinguished from narrowband and spread spectrum technologies in the sense that the bandwidth of the signal of ultra wideband type is typically between about 25% and about 100% of the central frequency, or else is greater than 1.5 GHz. Moreover, instead of transmitting a continuous carrier modulated with information or with information combined with a spreading code, which determines the bandwidth of the signal, ultra wideband technology involves the transmission of a series of very narrow pulses. For example, these pulses may take the form of a single cycle, or monocycle, having a pulse width of less than 1 ns. These pulses that are extremely short in the time domain, when transformed into the frequency domain, produce the ultra wideband spectrum that is characteristic of UWB technology.
In UWB technology, the information conveyed on the signal may be coded, for example, by a digital pulse interval modulation (DPIM). With such a modulation, the value of the spacing between two consecutive pulses of the pulse train codes the value of the information. Furthermore, each of the possible spacings is an integer multiple of a base duration. The decoding of the pulse train comprises, in particular, the detecting of the positions of the various pulses so as to determine the values of the durations separating them.